3,3a-dihydro-2h,9h-isoxazolo(3,2-b)(1,3) benzoxazin-9-ones

ABSTRACT

CHEMICAL COMPOUNDS OF THE FORMULA:   XN-,2-R1,3-R2-3,3A-DIHYDRO-2H-9H-ISOXAZOLO(3,2-B)(1,3)-   BENZOXAZIN-9-ONE   WHEREIN N IS 1 OR 2 AND WHEREIN EACH X IS HYDROGEN, HYDORXY, HALOGEN, LOWER ALKYL, LOWER ALKOXY, NITRO, AMINO, ACETAMIDO, SULFONAMIDO OR TRIFIUOROMETHYL AND EACH R IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND LOWER ALKYL SAID COMPOUNDS HAVE VALUABLE ANTI-INFLAMMATORY, ANTIPYRETIC AND DIURETIC ACTIVITIES IN STANDARD LABORATORY ANIMALS.

United States Patent 3,598,814 3,3a-DIHYDRO-2H,9H-ISOXAZOL0(3,2-b)(1,3) BENZOXAZIN-9-ONES David B. Reisner, Hightstown, Bernard J. Ludwig, North Brunswick, Harold M. Bates, Nutley, and Frank M. Berger, Princeton, N..l., assignors to Carter-Wallace,

Inc., New York, N.Y.

No Drawing. Continuation-impart of application Ser. No. 826,738, Mar. 24, 1969. This application Jan. 21, 1970, Ser. No. 4,745

Int. Cl. C07d 87/16 U.S. Cl. 260-444 21 Claims ABSTRACT OF THE DISCLOSURE Chemical compounds of the formula:

wherein n is 1 or 2 and wherein each X is hydrogen, hydroxy, halogen, lower alkyl, lower alkoxy, nitro, amino, acetamido, sulfonamido or trifluoromethyl and each R is selected from the group consisting of hydrogen and lower alkyl. Said compounds have valuable anti-inflammatory, antipyretic and diuretic activities in standard laboratory animals.

CROSS REFERENCE TO RELATED APPLICATION 3,593,814 Patented Aug. 10, 1971 ice wherein n is 1 or 2 and each X is hydrogen, hydroxy, halogen, lower alkyl, lower alkoxy, nitro, amino, acetamido, sulfonamido or trifluoromethyl and each R is selected from the group consisting of hydrogen and lower alkyl. When X is amino the compounds can be used in the form of the non-toxic pharmaceutically acceptable acid addition salts, such as the hydrochloride, citrate, maleate, and the like. As used herein and in the appended claims, the terms lower alkyl and lower alkoxy signify alkyl and alkoxy radicals having from 1 to 6 carbon atoms.

The compounds of the invention can be conveniently prepared according to the following synthetic route:

R R, CH COOH OH base In the first reaction step, a salicylhydroxamic acid, substituted or unsubstituted, is reacted with a substituted or unsubstituted acrolein, in a medium such as acetic acid or ethanol in the presence of hydrogen halide to yield the desired intermediate. The reaction is carried out at a temperature of from about 20 to about C. The intermediates, Which can be classified as 2 (2 haloalkyl)- 2,3 dihydro 3 hydroxy 4H 1,3 benzoxazin 4- ones, are also novel compounds.

Cyclization of the intermediate compound under basic conditions yields the desired product. Said cyclization can be carried out using organic or inorganic bases in the appropriate solvent.

Table I, which follows, sets forth the physical constants of a number of novel intermediates of the present invention. Table II sets forth the physical characteristic of a representative number of the novel compounds.

TAB LE I N CH-CHY X M.P., C.

Formula Calculated 147-149 li-CHaO 154-155 7-C F3 134 135 tdbdhitdt ll tgm g1 mmmgmmmm 5:

B Fluorine: Calculated, 19.30; Found, 19.53.

Analysis, percent lllalculated Found .P., Other Other ii r il iaz l R R2 Method 0. Formula C H N Elements H N elements H H B 89. 5-90. 5 CHJHQNO: 62. 82 4. 74 7. 33 62. 80 4. 70 7. 28 H A, 148-149 C1oH3C1NO3 53. 22 3. 57 6. 21 53. 52 3. 54 6. 30 H 13 1132-138 CnHnNO; 64. 38 5. 40 5. 83 64. 84 6. 68 6. 79 H C 118-120. 5 CnHnNOa 54. 38 5. 40 5. 83 64.33 5. 49 6. 76 C H; A 105-108 UnHnNOa 64. 38 5. 40 6. 83 64. 30 5. 43 6. 66 H C 192-193 CmHsNzOs 50. 85 3. 41 11. 86 50. 68 3. 33 11.66 H A 164-165 C11H11NO4 59. 73 5.01 6. 33 59. 67 5. 22 6. 28 H A 158-159 CnHsFsNOs 51. 00 3. 09 5. 41 51. 23 3. 17 6. 35 H A 147-149 CuHmClNO 55. 20 4. 22 5. 86 65. 24 4. 17 5. 75 H 211-212 CmHmNzOa 58. 25 4. 89 I13. 59 58. 11 4.81 13. 47 5,7-diCl H D 151-153 CmH7Cl2NO3 46. 29 2. 70 5. 38 46. 22 2. 72 5. 45 12 5,7411 1 CH3 H A 172-174 CuHoChNOa 48. 21 5. 31 5. 11 48.05 3. 34 5. 00

l Chlorine. b Flourine.

The following Examples 1 and 2 illustrate the preparation of the 7 chloro 3.3a dihydro 2H,9H isoxazolo(3,2-b)(1,3)benzoxazin 9 one (Compound 2, Table II) EXAMPLE 1 Preparation of 6-chloro-2-(2-chloroethyl)-2,3-dihydro-3- hydroxy-4H-1,3-benzoxazin-4-one (Table 1) Hydrogen chloride gas (36.5 g.) was added to 300 ml. of glacial acetic acid at about 10 C. To one-half of this solution was added 88 g. of S-chlorosalicylhydroxamic acid, and then 28 g. of acrolein and the remaining half of the hydrogen chloride-acetic acid mixture were introduced simultaneously with stirring and cooling at a rate to maintain a temperature of 25 to 50 C. The resulting mixture was stirred and heated at 50 C. for one and one-half hours and then allowed to stand at room temperature for 2 hours. Ice was then added and solid was removed, washed well with water and air-dried. It weighed 100 g. and melted at 8090 C. After several recrystallizations from ligroin, the melting point was raised to 1l4l15 C.

EXAMPLE 2 Preparation of 7-chloro-3,3a-dihydro-2H,9H-isoxazolo (3,2-b) (1,3)benzoxazin-9-one (Compound, 2, Table II) Method A.-96 g. of crude 6-chloro-2-(2-chloroethyl)- 2,3 dihydro 3 hydroxy 4H 1,3 benzoxazin-4-one was dissolved in 150 ml. of 10% aqueous solution of sodium hydroxide. After several minutes, a solid precipitated. Mixture was diluted with water, filtered and solid was washed with water and air-dried. The product weighed 67 g. and melted at 148-149" C. On recrystallization from ethyl acetate, 7 chloro 3,3a dihydro- 2H,9H isoxazolo(3,2-b) (1,3)benzoxazin 9 one melting at 148149 C. wasobtainedg Method B.-A solution of 64 g. of crude 6-chloro-2- (2 chloroethyl) 2,3 dihydro 3 hydroxy 4H 1,3- benzoxazin-4-one and 13.5 of sodium methoxide in 450 ml. of ethanol was heated at reflux for one-half hour, cooled and filtered. The filtrate was evaporated to dryness and residue was recrystallizer several times from ethyl acetate giving a product which then melted at 148 149 C.

The following Example 3 illustrates the preparation of 2 methyl 3,3a dihydro 2H,9H isoxazolo (3,2-b) (1,3)benzoxazin-9-one (Compound 4, Table II by the alkaline cyclization of 2 (2 chloropropyl) 2,3 dihydro 3 hydroxy 4H 1,3 benzoxazin 4 one. The latter intermediate was prepared by the reaction of salicylhydroxamic acid, crotonaldehyde and hydrogen chloride following the procedure detailed in Example 1.

EXAMPLE 3 Preparation of 2-methyl-3,3a-dihydro-2H,9H-isoxazolo (3,2-b) (1,3)benzoxazin-9-one (Compound 4, Table II) Method C.A mixture of 14 g. of crude 2-(2-chloropropyl) 2,3 dihydro 3 hydroxy 4H 1,3 benzoxazin-4-one and 50 ml. of 5% aqueous solution of sodium carbonate was shaken and warmed. It was then cooled and the solid was removed by filtration, washed with water, and air-dried. The crude product weighed 11 g. and melted at 1l2-116.5 C. After recrystallization from ethyl acetate, the purified 2 methyl 3,3a dihydro- 2H,'9H isoxazolo(3,2-b)(1,3) benzoxazin 9 one melted at 118-1205 C.

EXAMPLE 4 Preparation of 5,7-dichloro-3,3a-dihydro-2H,9H-isoxazolo (3,2-b)(1,3)benzoxazin-9-one (Compound 11, Table H) Method D.-2l.4 g. of crude 6,8-dichloro-2-(2-chloroethyl)-2,3-dihydro 3 hydroxy-4H-1,3-benzoxazin-4-one was converted to 17.6 g. of 5,7-dichloro-3,3a-dihydro-2H, 9H-isoxazolo(3,2-b) (1,3) benzoxazin-9-one (M.P. 149- 150 C.) with 375 ml. of a dilute aqueous solution of am:

monium hydroxide. The melting point was raised to 151- 153 C. after recrystallization from ethyl acetate.

The following Example 5 illustrates the preparation of the 7-amino-3,3a-dihydro-2H,9H isoxazolo(3,2-b)(l,3) benzoxazin-9-one (Compound 10, Table II).

EXAMPLE 5 Preparation of 7-arnino-3,3a-dihydro 2H,9H isoxazolo (3,2-b) (1,3)benzoxazin-9-one (Compound 10, Table 11 The compounds of the present invention are useful as a result of their valuable pharmacological properties, for example, they are valuable anti-inflammatory agents, as evidenced by their ability to inhibit the local edema formation characteristic of inflammatory states when administered systemically to warm-blooded animals.

The procedure described below (Winters et al., Proc. Soc. Exp. Biol. Med., 111, 544 1962) was used to establish the effectiveness of these compounds in the hind paw edema induced by carrageenin in the rat. This procedure is considered suitable for demonstrating anti-inflammatory acitvity of drug compounds in laboratory animals.

Male rats of the Sprague-Dawley strain (Charles River Laboratories) weighing 100:20 grams were used for this study. Six animals were used for each drug dose. The drugs were suspended in 1% aqueous solution of gum acacia, and each rate received 10 mL/kg. of the appropriate concentration of drug suspension by oral intubation; controls were given a similar volume of the vehicle. One hour later, edema in the right hind paw was induced by the subplantar injection of 0.05 ml. of 1% calcium carrageenin dissolved in 0.15 N sodium chloride. The volume of the foot was determined immediately and again 3 hours later. The difference was recorded as edema volume. Foot volume was measured by immersion of the foot in water at the level of the lateral malleolus, and determining the volume of water displaced by the foot. The ED may be defined as the dose in which edema formation is inhibited by 25% or more in 50% of the rats when compared to the mean value of the controls.

The compounds found effective using this procedure are identified below:

Compound No. (Table 11): (mg/kg, p.o.) 1 65:26

The anti-inflammatory activity of representative compounds of the invention were further demonstrated in the adjuvant-induced polyarthritis assay.

Male rats of the Sprague-Dawley strain (Charles River Laboratories) weighing approximately 200 grams were used. Ten animals were assigned randomly to each experimental drug or control group. The rats were weighed once a week and the drug doses were adjusted accordingly.

Poly arthritis was induced by the subplantar injection of an 0.5% suspension of heat-killed Mycohacterium tuberculosis in mineral oil to the right hind paw (Newbould, B.B., Brit. J. Pharmacol. 21, 127, 1963). The volume of the right (injected) and left (uninjected) hind paws was determined immediately before the induction of the arthritis and again 18 days later (approximately 18 hours after the last drug dose was administered); the difference was recorded as edema volume. Paw volume was determined by measuring the volume (mm. of water displaced by each paw when it was immersed in a water-filled graduated cylinder up to the level of the lateral malleolus.

In one experiment, the weights of the inoculated right hind paw and the uninoculated left hind paw were determined by severing the paws at the tibio-tarsal joint with a Harvard Guillotine, and weighing each paw on a Mettlcr top-loading scale. Edema weight was calculated by subtracting the paw weights of non-arthritic control rats from those of arthritic control and treated rats.

Test compounds were suspended in 1% gum acacia and were administered orally in a volume of mL/kg. Fresh suspensions were prepared daily. Controls received 1% gum acacia only. Drug treatment was started on the day that the polyarthritis was induced. The drug was given twice daily, 5 days a week (Monday through Friday) for two weeks and'for 4 days (Monday through Thursday) during the third week (total of 28 doses).

The result of a typical experiment is set forth in Table III, which follows.

TABLE III Percentage inhibition of Oral dose Assay paw edema e-I e, p Drug b.i.d.) dure 1 Right paw Left; paw

150 V 2 64 2 88 Compound 2, Table IL... 150 W 2 96 2 100 75 V 2 52 3 70 75 W 2 78 2 100 l V=Paw volume measured; W=Paw weight measured. 2 Controls vs. treated, P 0.001. 3 Controls vs. treated, P 0.01.

TABLE IV [Mean temperatures] 0 hour temperature, 2 hour, 4 hour, 6 hour, 8 hour, Group F. F. F. F. F.

Control (fevered) 102. 3 102. 1 101.7 101. 4 101. 3 Compound 2, Table II:

300 mg./kg., p.0 102. 2 99. 3 98. 2 98. 4 98. 8 fg./kg., p.0 102. 2 100. 5 99. 9 100. s 100. 6 75 mg./kg., p.o-. 102. 3 100. 8 100. 7 101. 2 101. 5 Control (non-fevered). 94. 8 98. 7 98. 7 98. 7 99. 1

1 Base temperature.

The diuretic activity of Compound 2, Table II, was also determined by non-fasted, non-waterloaded rats, using the method essentially described by Cummings et al., J. Pharm. Exp. Ther., 128, 414, 1960.

Male Sprague-Dawley rats (Charles River Laboratories) maintained in a die of Wayne Lab Blox R were used in this study. The animals, which weighed 200:20 grams, were given food and water ad libitum until the time of drug administration. They were then deprived of food and water for 18 hours; during this time period, urine was collected. The volume and pH of each urine sample was recorded, and an aliquot was used for the determination of sodium, potassium, chloride, and creatinine.

During the urine collection period, groups of 3 rats were placed in each stainless steel metabolism cage, which had been carefully washed and rinsed with distilled water. In addition to mesh floor screens, glass wool was placed in funnels to prevent fecal material from entering the collection of flasks. In recovery experiments, fluid loss was less than 5% The drug was suspended in 1% gum acacia and administered orally in a volume of 10 mL/kg. Control rats received 10 mL/kg. of 1% gum acacia only.

The data obtained from 4 separate experiments are shown in Table V.

TABLE V Electrolyte excretion Creatinine Dosage Mean Urine output {mEqX1O /3 rats/18 hours) excretion No. rat {mg/kg urinary, (ml/3 rats; (mg/3 rats/ Ratio Experiment No. Drug groups no.) pH 118 hours Na+ K+ Cl- 18 hours) Na+lK+ Compound 2 {5 1300 6. 1 26.51111. 6 21711112 1 40711133 1 19311114 1 11.81110. 4 0. 53 1 o .150 6. 0 21. 51112. 6 l93i32 41811126 173i28 11. 8:|:O. s o. 46 Controls 6 o. 5 10. 21114. 2 9811122 28311147 1431133 8. 5:12. 1 0. 35

4 {300 6. 5 11. 151113. 5 39611133 753:1:23 365i36 18. 01110. 6 0. 53 2 Compound 2 r 4 .100 6. 5 28. Hi5. 0 23711131 61511176 30211116 17. 61111.6 0.39 ,4 150 5. 5 131. 01113.0 223:1: 5 538i 27111117 18. 610. 6 0. 41 Controls B 6. 5 120. 31111. 5 17911116 44011133 196120 16. 51112. 1 0. 41

Compound 2 {4 M150 6. 0 L34. 3:115. 3 24311143 57911170 23511161 21. 61110. 8 0. 41 3 8 7 15. 5 122. 41110. 8 15011124 392138 17711126 13. 8:110. 8 0.38 Controls 1 6. 0 112. 81112. 7 981118 34211125 1501115 10. SiO. 3 0. 28

Compound 2 {4 11300 6. 5 22. 51110. 5 17011119 44911145 17311: 4 14. 01111. 3 0.38 4 4 .100 6. 0 13 51117. 5 16511148 44911162 20111130 13. 91112. 8 0. 37 Controls B 6. 0 13. 91111. 7 91i8 32311152 13811112 11. 41111. 5 0. 28

1 Standard deviation.

The pharmaceutical compositions of the present invention are prepared by incorporating the active ingredient with a suitable pharmaceutical carrier. The carrier must be of such nature that the novel compositions may be administered systemically to warm blooded animals. The term systemically, as used herein, means a mode of administration whereby the active ingredient, when given to warm blooded animals, is effective in the whole body and not merely at the locus of application. This includes parenteral and other methods of administration.

The active ingredients of the present invention are preferably adminstered orally in the form of tablets or capsules. Suitable solid pharmaceutical carriers which can be utilized include, for example, starch, lactose, sucrose, glucose, gelatin, and the like. When the composition is in the form of a solid, the active ingredient is generally in the amount of from about 25 to about 95% by weight of the total composition.

The active ingredients of the invention can also be dissolved in a liquid pharmaceutical carrier, such as for example, propylene glycol, polyethylene glycol, water, saline, and mixtures thereof, to form a solution suitable for injection. Such injectable solutions generally contain from about 0.05 gram to about 30 grams of active ingredient per 100 ml. of solution.

What is claimed is:

1. A compound of the formula:

wherein n is 1 or 2 and each X is hydrogen, hydroxy, halogen, lower alkyl, lower alkoxy, nitro, amino, acetamido, sulfonamido or trifluoromethyl and each R and R is selected from the group consisting of hydrogen and lower alkyl.

2. The compound of claim 1 wherein n is l X, R and R are hydrogen.

3. The compound of claim 1 wherein n is 1, X is halogen and R and R are hydrogen.

4. The compound of claim 1 wherein n is l, X is lower alkyl and R and R are hydrogen.

5. The compound of claim 1 wherein n is 1, X is lower alkoxy, and R and R are hydrogen.

6. The compound of claim 1 wherein n is l, X and R are hydrogen and R is lower al-kyl.

7. The compound of claim 1 wherein n is 1, X and R are hydrogen and R is lower alkyl.

8. The compound of claim 1 wherein n is 2, X is halogen and R and R are hydrogen.

9. The compound of claim 1 wherein n is 2, X is halogen, R is lower alkyl and R is hydrogen.

10. 3,3a-dihydro 2H,9H isoXazolo(3,2-b)(1,3)benzoxazin-9-one.

11. 7-chloro 3,3a dihydro 2H,9H isoxazolo(3,2-b) (1,3 )benzoaxaZin-9-one.

12. 2 methyl 3,3a dihydro-2H,9H-isoxazolo(3,2-b) 1,3 )benzoaxazin-9-one.

13. 3 methyl 3,3a dihydro-2H,9H-isoxazolo(3,2-b) 1,3 benzoaXazin-9-one.

14. 7 methyl 3,3a dihydro-2H,9H-isoxazolo(3,2-b) (1,3 )benzoaxazin-9-one.

15 7-nitro 3,3a dihydro 2H,9H isoxazolo(3,2-b) (1,3 benzoaxazin-9-one.

16. 7-methoxy-3,3a-dihydro 2H,9H isoxazolo(3,2-b) 1,3 benzoaXazin-9-one.

17. 6-trifluoromethyl 3,3a dihydro-2H,9H-isoxazolo (3,2-b) (1,3 )benz0xazin-9-one.

118. 2-methyl-7-chloro 3,3a dihydro-2H,9H-isoxazolo (3,2-b) 1,3 )benzoxazin-Q-one.

19. 7-amino 3,3a dihydro 2H,9H isoxazolo(3,2-b) 1,3 -benzoxazin-9-one.

20. 5,7-chloro-3,3a-dihydro 2H,9H isoxazolo(3,2b) 1,3 -benzoXazin-9-one.

21. 5,7-dichloro 3,3a dihydro-2-methyl-2H,9H-isoxazolo(3,2-b) 1,3 )benzoxazin-9-one.

References Cited UNITED STATES PATENTS 3,355,453 11/1967 Hasspacher 260244 HENRY R. J ILES, Primary Examiner *R. J. BOND, Assistant Examiner US. Cl. X.R. 424-1248 

